Ethics troubles complicated New Jersey Gov. Chris Christie's chances of becoming Mitt Romney's running mate last year, The New York Times reports is in an upcoming chronicle of the 2012 presidential campaign.
The Times reported that too many questions remained after Christie completed the vetting process and Romney had lingering concerns.
The details come four days before New Jersey voters head to the polls to determine if Christie gets a second term.
During a campaign stop Friday, he dismissed the report and told CNN that the authors are "just trying to sell books."
Christie's challenges were first reported Thursday night by Times national political correspondent Johnathan Martin and based on details of the book, "Double Down: Game Change 2012."
The highly anticipated book about the presidential election by Mark Halperin and John Heilemann, is expected to be a juicy tell-all about the inner-workings of the presidential campaign.
Those concerns included a Justice Department investigation of Christie's expenditures while he was a U.S. Attorney in New Jersey.
A 2010 report by the department's Inspector General concluded Christie --- among five top prosecutors investigated -- was the "the U.S. attorney who most often exceeded the government (travel expense) rate without adequate justification."
He also offered "insufficient, inaccurate or no justification" for most of those costs, and refused to meet personally with investigators about the discrepancies.
Christie was not identified by name in the government report, but government sources have said he was "U.S. Attorney C," CNN confirmed.
Romney adviser Beth Myers, who ran Romney's vice presidential search committee, told CNN that "Governor Christie complied fully with the Romney campaign's request for documents in a timely manner, including a complete medical report from his internist and cardiologist."
Romney ultimately chose Rep. Paul Ryan of Wisconsin as his running mate.
Biden vs. Clinton
President Barack Obama's closest advisers may have secretly considered replacing Vice President Joe Biden with Hillary Clinton on the 2012 ticket, but White House spokesman Jay Carney said Friday that it was never a remote possibility.
"Campaigns and pollsters test a lot of things," he told reporters at the daily White House briefing. "What I can tell you without a doubt is that the President never considered that and if anyone brought that to him, he would have laughed it out of the room, would never take it seriously."
Carney earlier told CNN's "New Day" that he knew "for a fact" Obama never considered it, later saying the idea was never brought to him.
He answered affirmatively when asked if Obama thought Biden would be a strong chief executive, saying that he had been an asset to the President in two campaigns and throughout the administration.
"Sure. I think the President picked Joe Biden as his running mate for the right reason, which is, if necessary, the vice president could be president. That's the first item on your checklist when you're picking your running mate," Carney said at the White House.
Asked about sizing up the potential Republican presidential field, Carney replied, "I think they all ought to run. It would be awesome."
Bill Daley, who was then Obama's chief of staff, said the swap wasn't necessary.
No one "thought that that was a good idea or needed to be done or should be done," Daley said on "CBS This Morning."
The Times obtained a copy of the book and reported that the President's top aides conducted "extensive group-sessions and polling in late 2011" to gauge whether dumping Biden could help bolster Obama's waning re-election hopes.
The book says Daley spearheaded the effort, despite their "close personal rapport," before ultimately deciding against the move when data showed that adding Clinton to the ticket wouldn't "materially improve Obama's odds."
Daley pushed back on the notion.
"Not for a moment was there a serious discussion or a belief that Joe Biden should be replaced, period," said Daley, a CBS contributor.